Ba2CaWO6-Sr2CaWO6赝二元系的研究

用差热分析、X射线物相分析和点阵常数的精确测定,研究了Ba₂CaWO₆-Sr₂CaWO₆赝二元系的相平衡和相变。发现在高温(860℃以上)时,形成连续固溶体。在室温时,在富Ba₂CaWO₆一侧,形成以Ba₂CaWO₆为基的固溶体;在富Sr₂CaWO₆一侧,形成以Sr₂CaWO₆为基的固溶体,相变点在成分为Ba₂CaWO:Sr₂CaWO₆=25:75(克分子比)处。同时研究了作为高压钠灯灯丝涂层材料的Ba_xSr_2-xCaWO₆的几个重要性质:电子发射和多次启动时的灯压升高等。发现成分为BaSrCaWO₆时,性质最好。 关键词：

INVESTIGATION OF THE PSEUDO-BINARY SYSTEM Ba2CaWO6-Sr2CaWO6

The phase equilibrium and transition in the pseudo-binary system Ba₂CaWO₆-Sr₂CaWO₆ have been investigated by means of DTA, X-ray powder diffraction, precise measurement of lattice parameters and other methods. A continuous solid solution was formed at high temperatures (above 860℃). At room temperature, a solid solution based on the structure of Ba₂CaWO₆ was formed on Ba₂CaWO₆-rich side and a solid solution with the structure of Sr₂CaWO₆ on Sr₂CaWO₆-rich side and a phase transition point was found at 25mol. per-cent of Ba₂CaWO₆.As a coating material for the filaments of high voltage sodium lamp, the important characters of Ba_xSr_2-xCaWO₆, the electron emission and the rise of the lamp voltage during multiswiching, were investigated. The best performance was found at the composition of BaSrCaWO₆.